Cellulose ester or ether plasticized with ethyl alpha-carbethoxyethoxyethyl carbonate



Patented Nov. 9, 1948 2,453,264 CELLULOSE as'ran on ETHER rms'rroizao WITH ETHYL ALPHA-CARBETHOXYETIL.

OXYETHY L CARBONATE Chessle E. Rehberg,

Glenside, Pa., assignor to United States of America as represented by the Secretary of Agriculture No Drawing. Original application September 28,

1944, Serial No. 556,241. Divided and this application November 7, 1945, Serial No. 627,269

3 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) This application is made under the act of March 3,1883, as amended by the act of April 30, 1928, and the invention lierein described and claimed, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This is a division 01' my abandoned application Serial No. 556,241, filed September 28, 1,944. This invention relates to cellulose esters or ethers plasticized with esters of hydroxy' acids wherein the hydroxyl group of 'the hydroxyester is acylated with an alkyl, alkenyl or alkoxyalkyl carbonic acid, which may be represented by the formula ROCOOCRR 'COORf ROCOOCR'R"COOR"'+HC1 The esters of this invention are typically clear, colorless, mobile liquids having low vapor pressure at ordinary temperatures and, because of their low volatility and good compatibility, are useful as plasticizers and solvents for many resinous materials. Those esters containing one or more reactive oleflnic double bonds are also useful when-polymerized alone. or with other polymerizable materials, particularly with the acrylic or vinyl type of monomer.

The following examples illustrate my invention and" the manner in which it may be practiced:

EXAMPLE I General procedure bonate is slowly added, the temperature of the mixture being kept below 40 C. When the mixing is complete, the mixture is slowly heated to 100 C., at which temperature it is maintained for 1-5 hours. After cooling, the material is washed twice with cold water, then'once with,

dilute hydrochloric acid, and again with water, then dried and distilled. A small additional amount of product can be recovered by extracting the washings with benzene or ether and combining the extracts with the main product.

Saturated brine may be used instead of water in washing those products which show appreciable solubility in water. Because of the very low vapor pressure of most of the compounds covered by this invention, it is advisable to distill them under reduced pressure.

Table 1, below, contains a l st of compounds prepared in accordance with this invention and data relative to yields and physical properties.

TABLE, 1

Alkyl alpha-carbalkoxyalkyl carbonates I ,1 m B. P., Press., Y I Yield, R R R R 0. mm. Hg ercent Hydrogen... Methyl R0 6 1. 4100 1.1587 58 -d0 i d 110 26 1,4118 1.1134 53 n-Butyl 136 18 1.4182 1.0325 54 Ally] 121) 23 1. 4280 1. 0770 Ethoxyethyl 00 1 1. 4229 1.0791 42 Methyl. 0B 7 1 4103 l. 0820 6% (1 S 3 7 1.4118 1.0734 i5 125 14 1. 4196 1.0604 61 115 '12 1.4180 1.0549 R4 102 2 1. 4410 1. 0790 04 114 2 1. 4230 1. 0442 78 1 1. 4221 1. 0206 82 123 7 l. 4237 l. 0038 20 124 21 1. 4202 1'. 0162 40 1 Sheets, films and other objects es es l'rom the examples listed in Table i, it is ap- 100' C. After this heat treatment, the resin was parent that a very wide variety of compounds I no longer soluble in common organic solvents.

can be prepared in accordance with this invention by varying the selection of the three essen- CELLULOSE DERIVATIVES PLABTICIZED tion components of the product: namely, (1) the 5 WITH ALKYL ALPHA-CARBALKOXYAL- chlorocarbonate, (2) the liiyd13lthcbtafl1l KYL CARBONATEB acid, and (3) the alcohol wit w c e y roxy acidis esteriiied. Because of the wide variety Maw J a or chlorocarbonates, hydroxy acids and alc h Two series or tests were made using the same which are available commercially or which can group of plasticizers, one on cellulose acetate and be readily synthesized, the number of combinathe other on ethyl cellulose. i

tions or these three components which can be In the first series, a mixture of 5 parts of cellused to prepare esters in accordance with thi lose acetate (acetone-soluble, high-medium visinvention is very large. By proper choice of cosity, low acetyll and 1 part of plasticizer was these thr e omp n t h p t s f th ill dissolved in 60 parts or a :1 acetone-methanol product can be controlled over a wide range and m xtu The ti was poured mm a flat m esters havin p p r needed f r n D and the solvent allowed to evaporate. Finally.

p s s ca be pr u F r xamp f r plasthe film was cured by heating 24 hours at 85 c.

ticizers, the volatility, water resistance, solubilh m was th n examined for compatibility,

ity, s ent p w r and ot r imp rta t pr p r- 2o brittleness, flexibility, andsoforth.

ties can be controlled to a large extent. In the other series, the same technique was A valuable property possessed by those esters used, except that equal parts of ethyl cellulose which contain one or more olefinic double bonds and plasticizer were dissolved in pure acetone.

is their ability to polymerize and to copolymerize The results of these tests are listed in the folwith other polymerizable monomers. 25 lowing table:

TABLE 2 No. Plasticizer Cellulose Acetate Series Ethyl Cellulose Series Ethyl Alpha-Carballylo POLY MERIZATION OF ALLYL ALPHA-CAR- BALLYLOXYETHYL CARBONATE' EXAMPLE II Examine n1 Allyl alpha-carballyloxyethyl carbonate was addedto methyl acrylate to make 1, 2, 5, and 10% solutions of the carbonate. 20 g. of these mixtures was added to 80 cc. of ethyl acetate containing 0.05 g. of benzoyl peroxide and the solutions thus obtained were placed in flasks in a water bath maintained at 75 C. After 24 hours, all the samples had polymerized, those containing 1 and 2%, respectively, of allyl alpha-c'arkallyloxyethyl carbonate giving sirupy solutions, that containing 5% giving a ropy, partially gelled solution, and that containing 10% giving a solid gel. Similar samples, using 5 and 10% 01' the carbonate, but with 0.5% of dodecyl mercaptan added to each, gave sirupy solutions with no trace of gelation.

prepared from the solutions of polymers obtained above were clear, colorless, flexible, and elastic. Similar objects which were insoluble in the common 'organic solvents were-produced by adding benzoyl peroxide (l-2% based on polymer, content) to the polymer solutions. After removal or the solvent,

the objects were heated for several hours. at 80- Methyl Alpha-Carbomethoxyethyl Carbonate. Ethyl A lpha-Carbethoxyothoxy ethyl Carbonate.

Ally] Alpha-Cnrhallyloxycthyl Carbonate n-Butyl Alphn-Carbo-aea-butoxymethyl Carnate. n-Amyl Alpha-Carbethoxyisopropyl Carbonate.

v the formation of the latter type of resin. On

yethyl Carbonate .do Do.

clear, slightly brittle. clear, slightly brittle. incompatible he clear, tough, flexible.

do Do.

All the plasticlzed compositions were completely compatible except 5 and 6 in the cellulose acetate v series.

Esters having two polymerizable double bonds in the molecule canbe polymerized alone or with other monomers, such as crylic esters, to produce resins which may be of the linear, soluble, thermoplastic type or of the cross-linked, insoluble type, depending on-the manner in which the polymerization is carried out. Thus, a high concentration of catalyst and a high temperature favor the other hand, by proper choice of catalyst, catalyst concentration and temperature, a soluble, thermoplastic resin may be obtained which can subsequently be converted into the insoluble type by incorporating additional catalyst and then heating. or by heat alone. Y

Thus, in preparing a copolymer of 99% methyl acrylate and 1% allyl alpha-carballyloxyethyl carbonate, about 1% of benzoyl peroxide may be incorporated and the polymerization eflected by heating the mixture, suitably in 10-40% concentration in an organic solvent which dissolves both the monomer and the polymer, at a moderate temperature, such as 30-80 C., until a viscous, sirupy solution of the polymer is obtained. This solution may be painted, sprayed, or otherwise used for coatings, impregnations, films, sheets, and so forth, or the solvent may be removed and the resin used for moldings.

After such fabrication, the finished product though most other cross-linked resins are hard 2. A plastic composition substantially consisting of cellulose acetate and ethyl alpha-curbethoxyethoxy-ethyl carbonate as plasticizer.

3. A plastic composition substantially consistcomposition substantially consist v guano in: of ethyl cellulose and ethyl alpha-oarbethoxyethoxy-ethyl carbonate, as plasticizer.

CHESSIE E. REHEERQ;

REFERENCES CITED '1 e'i'ollowing references are of record in the fllc i this patent:

mmn STATES PATENTS 10 Number Nome Date- Thurston Oct. 14, 1941 Ritchie Dec. 9, 1941 Muskat et al. .1 Feb. 27, 1945 Muskat et ai. Sept. 4, 1945 Muskat et a1. Sept. 4, 1945 Muskat et al. Oct. 30, 1945 Muskat et ai Oct. 30, 1945 

